Abstract
The aluminum overlay weld alloys with dispersed niobium carbide particles (NbCp/Al) were prepared by a plasma transferred arc welding process. The corrosion behavior of the NbCp/Al alloys was studied in a sodium chloride solution by means of immersion test, electrochemical techniques and scanning electron microscopy. The aluminum alloys used were pure Al, Al-Mg, Al-Mg-Si and Al-Cu. The addition of NbC particles shifted corrosion potentials of these alloys to positive direction. However, the pitting potentials were almost similar to that of overlay weld alloy without NbC particle. On immersion test in quiescent 0.5mol/l NaCl open to the air, the preferential localized corrosion for was observed all NbCp/Al alloys at the matrix-NbC particles and crystalline material interfaces.
